Basically if there are error saying that sender is throttled, then it means that the sending hourly limit has been reached.
The user need to wait for the next hour for the sending hourly limit has been reset again.
Steps to check for email throttling :-
Step 1 : Log in to smartermail
Step 2 : Search for the domain
Step 3 : Click on Edit
Step 4 : Click on “Throttling”
- We can see that the outgoing messages per hour for the domain is set to 100 only
- This is to prevent spam sending from the domain.
- You can add if you want to allow more messages per hour, but take note that it can have a risk of spamming activity for the domain.